NavigationService.GetNavigationService(DependencyObject) Method

Reference

Definition

Namespace:: System.Windows.Navigation

Assembly:: PresentationFramework.dll

Important

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Gets a reference to the NavigationService for the navigator whose content contains the specified DependencyObject.

public:
 static System::Windows::Navigation::NavigationService ^ GetNavigationService(System::Windows::DependencyObject ^ dependencyObject);

public static System.Windows.Navigation.NavigationService GetNavigationService(System.Windows.DependencyObject dependencyObject);

static member GetNavigationService : System.Windows.DependencyObject -> System.Windows.Navigation.NavigationService

Public Shared Function GetNavigationService (dependencyObject As DependencyObject) As NavigationService

Parameters

dependencyObject: DependencyObject

The DependencyObject in content that is hosted by a navigator.

Returns

NavigationService

A reference to the NavigationService for the navigator whose content contains the specified DependencyObject; can be null in some cases.

Exceptions

ArgumentNullException

The dependencyObject parameter is null.

Examples

The following example shows how a UserControl can retrieve a navigation service by calling GetNavigationService.

void getNavigationServiceButton_Click(object sender, RoutedEventArgs e) {
    // Retrieve first navigation service up the content tree
    NavigationService svc = NavigationService.GetNavigationService(this.getNavigationServiceButton);
    if (svc != null)
    {
        // Use navigation service

Private Sub getNavigationServiceButton_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
    ' Retrieve first navigation service up the content tree
    Dim svc As NavigationService = NavigationService.GetNavigationService(Me.getNavigationServiceButton)
    If svc IsNot Nothing Then
        ' Use navigation service

}
}

    End If
End Sub

Remarks

A navigator has a NavigationService that handles content navigation. WPF has two navigators: NavigationWindow and Frame. To process navigation requests and manage navigation lifetime, a navigator uses the WPF navigation service, which is implemented as the NavigationService class. Content that is hosted by a navigator can get a reference to the navigator's NavigationService by calling the GetNavigationService method.

GetNavigationService returns null when the dependencyObject:

Is a NavigationWindow.
Is a Frame that:
1. Is hosted by another navigator.
2. Has its JournalOwnership property set to UsesParentJournal.
Is not part of content that is hosted by a navigator.

WPF offers two shortcuts for acquiring a reference to the NavigationService:

The NavigationService that processed the navigation to a Page can be accessed from the Page itself by getting the value of its Page.NavigationService property.
The NavigationService that is used by a Frame to process navigation can be accessed by getting the value of the NavigationService property.

Applies to

Product	Versions
.NET Framework	3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
Windows Desktop	3.0, 3.1, 5, 6, 7, 8, 9, 10

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